The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
In conventional coordinated multi-point wireless systems, each mobile device measures interfering signals and reports back the channels of interfering base stations whose reference signal received power (RSRP) lies below a certain threshold. Each mobile device feeds back the full channel covariance matrix of all interfering cell channels that meet this threshold as well as the full channel covariance matrix of serving cell channels. The channel covariance matrices of each channel within the reporting set includes (M2−M)/2 complex numbers plus M real numbers, where M is the number of transmitting antennae of the mobile device. Coordinated multi-point wireless systems use this feedback to control the precoding direction of signals transmitted by the base stations in order to reduce the strength of interfering signals received by the mobile devices.